FXUS63 KMKX 080009 AAA AFDMKX Area Forecast Discussion...UPDATED National Weather Service Milwaukee/Sullivan WI 709 PM CDT Tue Jul 7 2026 .KEY MESSAGES... - Marginal to Slight Risk of severe thunderstorms late Wednesday afternoon and evening. Damaging winds and large hail are the main hazards. Locally heavy rain and urban and small stream flooding will be possible well into the night. - A continuation of scattered storms or redevelopment is forecast for Thursday. Locally heavy rain and urban and small stream flooding will remain possible. - Hot and muggy conditions return early next week. && .UPDATE... Issued 709 PM CDT Tue Jul 7 2026 Quiet weather will continue for the evening and overnight hours under the influence of surface high pressure centered to the south of the forecast area. Scattered cumulus early this evening will diminish, with few to scattered high clouds expected overnight. Temps are expected to be within a few degrees of normal overnight. In all, the forecast looks on track for the evening and overnight hours. DDV && .SHORT TERM... Issued 143 PM CDT Tue Jul 7 2026 Tonight through Friday: A pleasant and seasonal summer day will continue this afternoon with a lake breeze moving wwd into the inland counties. High pressure will shift se of the area tnt while a sfc trough develops from the central high plains into srn MN. Low to mid level warm, moist advection north of this feature will support clusters of thunderstorms from the nrn Great Plains into the nrn half of WI through Wed AM. For later Wed afternoon and night the sfc trough/cold front will slowly sag sewd toward srn WI with an upstream and slow moving shortwave trough approaching. The shortwave trough and cold front will slowly pass on Thu. MLCAPE will build to 1300-1800 J/KG by late Wed afternoon with effective shear around 20 kts. CAMs and deterministic models still have some timing differences but there has been a quicker trend for the onset of storms. A low end severe threat for damaging winds and large hail is forecast mainly north of Madison and Milwaukee. For later in the evening and overnight, more of a locally heavy rain and urban and small stream flood potential will exist. This is supported by a wly 25 kt low level jet and associated thetae advection within the thermal ridge and the approaching weak shortwave trough. This is in conjunction with PWATs of 1.5-2.0 inches and weak corfidi vectors. The CAMs and model QPF suggest the flood threat should remain isolated. Ongoing scattered storms and additional storms are then expected on Thu with the passage of the cold front and shortwave trough. Only marginal CAPE is expected with rather weak effective shear continuing. Thus the severe threat will be very low with more of a concern for urban and small stream flooding once again. Nely winds will bring a slightly cooler and drier airmass for Friday as high pressure builds from the nrn Great Lakes into WI. Seasonal temps and humidity is forecast. Gehring && .LONG TERM... Issued 143 PM CDT Tue Jul 7 2026 Friday night through Tuesday: Synopsis: The slow-moving surface front responsible for Wednesday & Thursday's thunderstorm chances will be near or just south of the state line Friday evening. If the feature remains close enough to the border, it could trigger a few more scattered storms over far southern Wisconsin Friday evening before shifting south this weekend. Pronounced upper ridging will build into the northern Great Plains from the Great Basin this weekend, reaching maximum strength and amplitude over the Upper Mississippi Valley early next week. With the center of the ridge in close proximity, large-scale subsidence will keep conditions dry from the weekend through the conclusion of the long term period. Beneath the subsidence, south to southwesterly low level winds will advect a very warm Great Plains air mass into the area. Heat will thus return to southern Wisconsin from the weekend into early next week. Elevated humidity will accompany the hot temperatures. Friday Evening: Could see a few scattered storms in far southern Wisconsin (along/south of I-94 & US-18) if a slow-moving surface front remains close enough to the state line. Precise frontal progression up to this point in the period will be heavily driven by afternoon/evening thunderstorms & attendant outflows on Wednesday and Thursday, which thus makes it difficult to know where exactly it will set up at this time. Most available guidance suggests it will be far enough south to preclude any thunderstorm development in southern Wisconsin Friday evening, though there are a few solutions hinting that the front could remain closer to the state line. Have thus maintained 15-20% precip probs from the NBM in the afternoon update, with further refinements to come as forecast confidence increases Wednesday-Thursday. Sunday through Tuesday: Hot and humid conditions return to the area thanks to renewed ridging building in from the west. Currently appears that afternoon heat indices in the 90s will be a good bet, particularly on Monday and Tuesday. How high readings reach and whether/not heat headlines will become necessary will ultimately depend on the depth and quality of moisture in place across the region, which remains a source of uncertainty this far out. Will be monitoring trends and refining the forecast as this portion of the period draws closer. Quigley && .AVIATION... Issued 709 PM CDT Tue Jul 7 2026 Quiet weather will continue for the evening and overnight hours under the influence of surface high pressure centered to the south of the forecast area. Scattered cumulus early this evening will diminish, with few to scattered high clouds expected overnight along with light winds. A chance for shower and storms is expected to gradually increase from the north late Wednesday morning into the evening hours. Locations along and north of I-94 have the best chance for seeing scattered showers/storms tomorrow through the evening hours. A few strong to severe storms will be possible in the afternoon and evening hours. Widespread southwest winds 5-10 knots tomorrow may become south to southeast by early afternoon near the lake. Scattered to broken cumulus around 5 kt feet is expected tomorrow, with some lower ceilings possible north towards Fond du Lac and Sheboygan by the evening hours. DDV && .MARINE... Issued 143 PM CDT Tue Jul 7 2026 High pressure around 30.1 inches over Lake MI and lower MI will shift southeast into the lower Great Lakes and the Ohio Valley for Wednesday. Expect light south winds over the northern portions of the lake this afternoon, with light and variable winds to the south. Modest south southwest winds will then develop tonight and continue on Wednesday, as weak low pressure around 29.8 inches and an accompanying cold front approaches from the Northern Great Plains. Modest southwest winds Wednesday night will become northwest to north behind the frontal passage Thursday into Friday, with high pressure around 30.0 inches building into the the Upper Great Lakes region. Gehring && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...None. && $$ Visit us at weather.gov/milwaukee Follow us on Facebook, X, and YouTube at: www.facebook.com/NWSMilwaukee www.x.com/NWSMilwaukee www.youtube.com/NWSMilwaukee